Endoscopic surgery often requires grasping or cutting bodily tissues and organs that are situated at some distance from the surgeon's hand. Various prior art linkages have been devised for converting a surgeon's manual efforts at the handle end of a surgical instrument into opening and closing of the instrument's jaws some distance away. Such prior art instrument's typically consist of a pair of articulated jaws, and a handle mechanism comprising two members, one movable with respect to the other, which can conveniently be manipulated so as to cause the jaws to open and close. Serrations, blades, or other features (depending upon the use for which the tool is intended) enable the jaws to perform various surgical functions, such as grasping or cutting. The articulated jaws are located at the distal end of a relatively long extension of the handle mechanism.
When operating the jaws of typical tools as described above, surgeons have experienced difficulty in grasping slippery tissues because the jaws close first at their rear ends and thereby tend to propel or push the tissues out from between the jaws. Consequently trauma of the tissues may result from repeated and increasingly aggressive attempts to grasp the tissue.